Depth Perception

Question 1

binocular disparity

Answer 1

the differences between your two retinal images for the same scene

Question 2

binocular summation

Answer 2

combining the two eyes’ signals allows inferences that aren’t possible with one

allows for stereopsis

Question 3

stereopsis

Answer 3

perception of depth calculated via multiple view points (i.e. 2 eyes)

Question 4

monocular vs. binocular

Answer 4

mono - 1 eye

bi - 2 eyes

Question 5

depth cues

Answer 5

information in environment that tells you how distance is being tracked

Question 6

monocular depth cues

Answer 6

occlusion
- relative cue of order

relative size/height
- smaller items must be further away
- higher objects are further

texture gradients
- at further distances, textures become smaller, tighter and their spatial frequency increases

aerial perspective
- brain understands that light scatters as it moves through our atmosphere
- further away = hazy

linear perspective
- lines that are // in the 3D world will appear to converge as they extend away from POV, aka vanishing point

motion parallax
- objects closer to you will pass by more quickly than objects further away

Question 7

monocular cues rely on previous knowledge, aka …

Answer 7

familiar size
- we use object knowledge to make assumptions about depth

ex) hand that is big is closer to us, not just a big hand

Question 8

If an object’s color is becoming less vivid, and more
white (not more black), it is changing in what factor?

a) Hue
b) Saturation
c) Brightness
d) Opponency

Answer 8

B

Question 9

why do many species have 2 eyes?

Answer 9

triangulation
- can figure out the relative distance of an item by knowing a distance between 2 points (your eyes) and the angles at which the item is to those 2 points

if you know 2 angles of a triangle you can figure out 3rd one

Question 10

convergence in eye position

Answer 10

turning inward for near objects

Question 11

divergence in eye position

Answer 11

turning outward for far objects

Question 12

corresponding retinal point

Answer 12

seeing one image of object with 2 eyes/retina images

Question 13

Horopter (Vieth-Muller circle)

Answer 13

anything on this ring in your retinal image will not have binocular disparity

Question 14

Stereopsis Zone/Panum’s Fusion Area

Answer 14

zone along the Horopter ring

if object is in this zone but not along ring, it will have a small enough disparity that your brain can overrule it to allow you to see one object with 2 eyes

Question 15

diplopia

Answer 15

double vision caused by disparity past the Panum’s Fusion Area

Question 16

disparity types

Answer 16

crossed = object is closer than fixation

uncrossed = object is further than fixation

Question 17

stereoacuity

Answer 17

the smallest degree of difference in binocular disparity that can generate a sensation of depth

Question 18

free fusion

Answer 18

you can actively cross or uncross your vision to produce 3D images in stereographic images

Question 19

dichoptic

Answer 19

2 eyes getting different inputs

what original 3D movies relied on to transmit different information to each eye

Question 20

correspondence problem

Answer 20

the brain trying to figure out how things match up when 1 retina is receiving different information than the other

also when you can only see certain things in one eye but not the other (slide 47)

Question 21

binocular rivalry

Answer 21

when two eyes are getting different inputs, can compete for visual dominance

Question 22

3 things that affect correspondence problem

Answer 22

spatial frequency
- lower spatial frequency information is generally easier to achieve correspondence (fewer fine details to match)

uniqueness
- any given feature should be represented exactly 1 time in each retinal image

continuity
- neighboring points (except at edges of objects) should be at similar distances

Question 23

evidence that some cells code for _____ while others code for ____

Answer 23

correspondence; disparity

Question 24

where is the first place that cells respond to both eyes?

Answer 24

V1

Question 25

stereoblindness

Answer 25

inability to make use of binocular disparity as a depth cue

can result from childhood visual disorder

most people who are stereoblind don’t realize it

Question 26

strabismus

Answer 26

two eyes are misaligned and brain doesn’t account for this difference

one eye has the object reflected on the fovea while the other eye has the image reflected on a nonfoveal area

Question 27

esotropia vs. exotropia in strabismus

Answer 27

eso - eye deviates inward

exo - eye deviates outward

Question 28

which of these woild not provide depth information to a person with only one eye?

motion parallax
aerial perspective
dichoptic viewing
relative height

Answer 28

dichoptic viewing

Question 29

Pia is staring at a dog in the distance. There is also a cat closer to her than where she is fixated. What is true about her vision of the cat if she doesn’t moved her fixation, assuming the cat is not within Panum’s Fusion Area?

the cat will be seen with crossed disparity
the cat will be seen with uncrossed disparity
the cat will be seen with stereopsis
the cat won’t be seen at all

Answer 29

the cat will be seen with crossed disparity